Re: Mesozoic non-dino papers: marine reptiles, turtles, labyrinthodonts

[David Marjanovic <david.marjanovic@gmx.at>]

> Ylenia Chiari, Vincent Cahais,  Nicolas Galtier and Frederic Delsuc
> (2012) Phylogenomic analyses support the position of turtles as the
> sister group of birds and crocodiles (Archosauria). BMC Biology 2012,
> 10:65 (provisional version) doi:10.1186/1741-7007-10-65
> http://www.biomedcentral.com/1741-7007/10/65/abstract NOTE: pdf is
> Open Access
>
> Abstract (provisional)
>
> [...] In this study, we used next-generation sequencing to obtain
> seven new transcriptomes from the blood, liver, or jaws from four
> turtles, a caiman, a lizard, and a lungfish.

Nice, but a larger taxon sample couldn't hurt, in particular three 
lissamphibians, more squamates (in particular a gecko and a dibamid), 
and a tuatara...

> The use of more simplistic  models of nucleotide substitution for both
> concatenation and species tree reconstruction methods leads to the
> artefactual grouping of turtles and crocodiles, most likely because
> of substitution saturation at third codon positions.

Ha. =8-)

> Relaxed molecular clock methods  estimate the divergence between
> turtles and archosaurs around 255 million years ago.

Good, this puts that divergence right into the extremely diapsid-poor 
Late Permian! Much better than the mid-/late Triassic estimates of 
earlier papers.

I'll have to download and read all three turtle papers.

> Triassic Labyrinthodonts
>
> I. V. Novikov (2012) New data on trematosauroid labyrinthodonts of
> Eastern Europe: 4. Genus Benthosuchus Efremov, 1937. Paleontological
> Journal 46(4): 400-411 DOI: 10.1134/S0031030112040089
> http://www.springerlink.com/content/u6g87m472u085tq7/
>
> The trematosauroid genus Benthosuchus Efremov, 1937 is revised and
> its diagnosis is emended. This genus includes the previously
> established B. sushkini, B. korobkovi, and B. bashkiricus, and the
> new species B. gusevae described here. The new form is archaic
> relative to congeners and is similar in a number of characters to the
> archaic capitosaurid Wetlugasaurus samarensis, which confirms direct
> affinity of the two genera.

Well, yes. *Wetlugasaurus* has been a textbook trematosauroid since at 
least 2000. It is, sadly, entirely possible that nobody in Russia has 
had the money to acquire this (Western) literature.